Adamasu No Majotachi Manga :

Kitou Yukinari is an ordinary high school boy. However, while playing a game of pocket pool one day, he suddenly felt as if he was passing a kidney stone. But this kidney stone was shiny and pink?

A trip to the hospital shows that Yukinari has a medical malady called Adamasu Syndrome - in short, whenever he jets his juice, a little diamond pops out of his saltshaker. Of course, it's painful as hell, to the point where even the act of popping the champagne bottle will shave off his lifespan. And of course, once his secret comes out, dozens of women flock to seduce him, their best friend now stuck inside his best friend. Can Yukinari survive when the world wants to sell his seed?